Electric horn



July28,1936;, G. ZE.N.NGER' 2,0 8,98

ELECTRIC HORN Filed Oct. 24, 19:52

Patented July 28, 1936 Gustav Zeininger, Obegen,

Bcsch er to Robert Stuttgart,

Application The present invention relates to electric horns,particularly for vehicles.

In electromagnetic horns for motor vehicles, the armature is rigidlysecured, as a rule, to the diaphragm by a screwed bolt.

- The diaphragms are ordinarily of sheet metal and are rigidly clampedat their margins so that there exist always certain tensions or strainsin the diaphragm and also in the rigid fastening .10 of the armaturewhich tend to prevent the diaphragm from vibrating exactly axially or ina direction perpendicular to the plane of the diaphragm and theoperation of the entire vibrating system is forced or constrained. Suchdis- 15 placed and unequal vibration of the diaphragm and armatureresults in variations in the tone; anddiiierencesinthesizeoitheairgapwiliaffeet very materially the proper operation of the horn.Furthermore, the purity of the tone is impaired because such impropervibration increases the wear on the interrupter contacts and on the i 7guide for the diaphragm and armature. The present invention has for itsobject to remove the drawbacks which result from the usual rigidfastening of the armature to the diaphragm.

For this purpose, according to the invention the armature is secured tothe-diaphragm by a bolt or similar fastening means with theinterposition of a resilient member mounted coaxially of said bolt andresilient uniformly to the axis thereof so as to press uniformly on thediaphragm, the said resilient member being tensioned to such an extentthat it behaves like a rigid member in holding the armature anddiaphragm together but is sufiiciently resilient to avoid or compensatefor undesirable stresses consequent upon fastening with rigid means. 7

To employ nuts, together with a slotted washer, for securing thearmature is not novel, but these slotted washers are not suitable forthe present purpose, because they are not resilient uniformly to theaxis of the fastening bolt and consequently only produce a veryunilateral stifiening or stay- Y ing with resultant undesired tensionsor strains. The invention is more particularly described with referenceto the accompanying drawing in which three examples or construction ofthe invention are illustrated and in which:- Figure 1 is a longitudinalsection through one 543 example.

Figure 2 a longitudinal section through the second example, and

Figure 3 a cross-section through a curved sprlngy disc for use in thethird example of con- 55 structionctober 24, 1932, Serial No. 639,363

- November 5, 1931 In Figure 1, an electromagnet I has a plateshapedarmature 2, which is secured by a bolt 3 to the diaphragm d.- Aplate-shaped oscillator 5 is connected to the diaphragm A by the bolt 3,

which has a cylindrical enlarged part, which is 5 side of the diaphragm4 is a disc I I which carries a pin 12 for centering the armature 2.Between the disc H and the oscillator 5 a distance disc I3 is arranged,which prevents the diaphragm 4 when oscillating from touching theoscillator 5. The free end of the bolt 3 is provided with a thread whichcarries a nut M which bears through a helical spring I5 against theoscillator 5. 4

The ball-joint mode of fastening the armature 2 enables an exactadjustment of the armature 2 in a plane parallel to its attraction face.The air gap between the armature 2 and its attraction time 'may, ifdesired, be adjusted by inserting a suitable washer between the armature2 and the intermediate piece 8. The fastening nut it is finallytightened up and then again slackened by about a quarter turn. By thismeans undesired tensions in the diaphragm and armature fastening arecompensated for. Consequently, the note produced is much more uniformthan in the rigid screwing up of the oscillating system; also smalldifierences or variations in the exact size of, the air gap arecompensated for so that such great care in adjusting the air gap aswould otherwise be necessary need not be taken. The adjustment of thehorn is thereby much less delicate than in the rigid fastening and theoscillating system works without constraint, whereby reliable operationis ensured even after long use.

It is not necessary that the springy member should be supported againstthe fastening nut. On the contrary, the springy member may, for example,be displaced even to the other end of the bolt 3, as shown in Figure 2.The construction therein shown is essentially the same as in the firstexample, except that the bolt 3 is carried through to a flange I1 andthe ball end face of the intermediate piece I bears against theconeshaped recess 9 of an intermediate disc l8. The spiral spring, heremarked I9, is compressed between this intermediate disc [8 and theflange l1, and the fastening nut I4 is tightened against instead of thespiral spring I5.

As will be seen from Figures 1 and 2, the airgap between the armature 2and its attraction face is not appreciably varied by adjusting thespring l5 or I 9 by means of the bolt 3 in the manner described.

There is nothing to prevent the resilient fastening of the armaturebeing also used in horns armature and said diaphragm, a ball and socketwithout an oscillator. In this case, the distance piece l3 and theoscillator 5 are simply omitted. The use of a ball-joint type ofarmature adjustment is also not necessary, and another mode ofsupporting the armature may be adopted than by the guide spring 6. Ideclare, that what I claim is: 1. An electromagnetic horn comprising acasing, an electromagnet mounted in said casing, an armature having anopening therein, an interrupter operated by said armature, a diaphragmsecured at its periphery to said casing and having an opening therein, abolt having an abutment thereon passing through the openings in saidjoint between said armature and said bolt, and a member resilientuniformly to the axis of said bolt coacting with the abutment on saidbolt to exert a high tension on said diaphragm and said armature toresiliently clamp said armature and diaphragm together and toresiliently mount said armature on said diaphragm.

- 2. An electromagnetic horn comprising a casing, an electromagnetmounted in said casing,

' an armature having an opening therein, an interrupter operated by saidarmature, a diaphragm secured at its periphery to said casing and havingan opening therein, a bolt having an abutment thereon passing throughthe openings in said armature and said diaphragm, and a member"resilient uniformly to the axis of said bolt and arranged co-axially onsaid bolt in the chamber formed by said casing and said diaphragm actingI on said diaphragm and said armature and coacting with the abutment onsaid bolt to resiliently clamp said armature and diaphragm together andto resiliently mount said armature on said diaphragm.

3. In an electromagnetic horn, the combination with a casing, avibratory diaphragm secured at its periphery to said casing and anelectromagnet secured to said casing, of an armature, fastening meanscarried by said diaphragm for securing said armature thereto, andresilient means-mounted coaxially of said fastening means andresilientuniformly to the axis thereof, said resilient means acting on saiddiaphragm and said armature and coacting with said fastening means toresiliently clamp said armature and diaphragm together and toresiliently mount said armature on said diaphragm, said resilient meansbeing tensioned so highly that said mounting is to said casing andspaced from said armature, a

by said fastening member and acting on said armature and diaphragm andcoacting with said fastening member to resiliently clamp said armatureand diaphragm together and to resiliently l5 mount said armature on saiddiaphragm.

5. An electromagnetic horn comprising a casing, an electromagnet mountedin said casing, an armature, a diaphragm secured at its periphery boltcarrying said armature and passing through said diaphragm to secure saidarmature thereto, and resilient means carried by said boltand-r'esilient uniformly to the axis thereof, said resilient meanscoacting with said bolt to resiliently clamp" said diaphragm andarmature together andfto resiliently mount said armature on saiddiaphragm, said resilient means being tensioned so highly that saidmounting is comparatively unyielding but is sufliciently resilient tocompensate 3 for undesired tensions in ithe diaphragm and mounting.

6. An electromagnetic horn comprising 9. casing, an electromagnetmounted in said casing, an armature having an opening therein; adiaphragm secured at its periphery to said'casing and having an openingtherein, a bolt" passing through the openings in said armature and saiddiaphragm, means spacing said. diaphragm from said armature on saidbolt, and a resilient member carried by said bolt and resilientuniformlyto the axis thereof acting on said armature and diaphragm toresilientlyurge them together against such spacing means and coactingwith said bolt to resiliently fasten said armature to said diaphragm.

7. An electromagnetic horn comprising a casing, an electromagnet mounted'in said'casing, an armature having an opening therein, "a dia; phragmsecured at its periphery to the casing'"50 and having an openingtherein, spacing means between said armature and diaphragm, a'boltpassing through said openings in said armature and diaphragm and havingan adjustable nut co-. operating with said bolt to adjustably clamp saidarmature, spacing means and diaphragm together, and a. spring membermounted on said bolt between said nut and the head of the bolt andresilient uniformly to the axis thereof t0 resiliently urge saidarmature and diaphragm to-' gether, the tension of said spring memberbeing adjustable by said nut without altering the spac: ing between saidarmature and diaphragm.

8. An electromagnetic horn as claimed in claim '7 in which theadjustable nut is arranged on the 65 end of the bolt towards the soundopening of the horn and the spring member is arrangedbetween theadjustable nut and the diaphragm.

9. An electromagnetic horn comprising a cas ing having an open end, adiaphragm, means securing the diaphragm to the open end of the casing,an electromagnet secured in the casing,'an armature for theelectromagnet, ball and socket means between the armature and-diaphragm.clamping means for holding the armature, ball and socket means anddiaphragm together wherebythearmatureissecuredtosaiddia,andspringmeansreaiiientuniiormlytotheaxis of said diaphragm and mountedbetween the clamping means and the armature, bail and 7 socket. anddiaphragm '10. An electromagnetic horn comprising a cas-,inghavinganopenendadiaphragmgmeansseeuringthediaphragmtotheopenendoitheeasing,an el In secured in the casing, an armature tor the e1eetromagnet,aballand socket joint between the armature-and diaphragm, a

- bolt for clamping the armature and diaphragm together whereby thearmature is secured to said diaphragm.-a ball and socket joint betweensaid bolt and said armature. and a spring resilient uniformly to theaxis of said bolt and mounted onsaidboltandurgingsaidarmatureanddiaphaem to eth 20' lhanetiohornasinelaimlmin which one element of each ofthe and socket 7 joints is loosely mounted onsaid bolt. said looselymounted elements mounting said armature on said bolt.

12. An electromagnetic horn comprising a easing having an open end, adiaphragm, means securing the diaphragm to the open end of the easing,an electromagnet secured in the casing, an

armature for the electromagnet, clamping means for holding said armatureand diaphragm together and for mounting said armature on said diaphragm,and spring means resilient uniform- 1y to the axis 0! said diaphragm andmountedbetween the clamping means and the armature and

